High-strength tufted pile fabric

ABSTRACT

The invention relates to a high-strength tufted pile fabric having a woven primary backing material of polypropylene or copolymer of propylene yarn, at least some of the yarn having a relatively flat cross section, which has been coated with about 0.2 to 12 percent, based on the weight of the yarn, of a lubricant material prior to penetrating tufts through the bodies of the yarn. The presence of the lubricant material on the yarns of the backing enhances penetration of the tufting needles and tufts into the yarns without the tufting needles causing the otherwise serious rupturing and shattering of the penetrated yarns which occurs during tufting of otherwise similar, but unlubricated, woven primary backing.

United States Patent HIGH-STRENGTH TUFTED PILE FABRIC 2 Claims, No Drawings U.S. Cl 112/410, 161/67 Int. Cl DOSc 17/02 Field of Search 112/410,

Reierences Cited Primary Examiner-James R. Boler Attorney-Emil W. Milan ABSTRACT: The invention relates to a high-strength tufted pile fabric having a woven primary backing material of polypropylene or copolymer of propylene yarn, at least some of the yarn having a relatively flat cross section, which has been coated with about 0.2 to 12 percent, based on the weight of the yarn, of a lubricant material prior to penetrating tufts through the bodies of the yarn. The presence of the lubricant material on the yarns of the backing enhances penetration of the tufting needles and tufts into the yarns without the tufting needles causing the otherwise serious rupturing and shattering of the penetrated yarns which occurs during tufting of otherwise similar, but unlubricated, woven primary backing.

HIGH-STRENGTH TUFTED PlLE FABRIC ARTlCLES AND METHODS This invention relates to improved primary backings for tufted pile fabrics, to improved pile fabrics comprising these packings and to methods for producing each.

It is present practice to employ a flat woven burlap-type backing material having yarns composed of jute, sisal, or sometimes paper. A serious disadvantage of this backing resides in the fact that the backing fabric is not of uniform thickness nor density. This characteristic is, of course, due in part to the actual interstices between the individual yarns and in part to the wide variation in thickness between individual yarns and varying thicknesses in the same yarn. AS a result, the tufting needles sometimes meet no resistance whatsoever. At the other extreme, the needles encounter maximum resistance due to the necessity for penetrating a thick yarn or double yarns. In still other instances the needles seem to push aside the yarns with little or no penetration of the yarn itself. As a result, the rows of pile yarn stitches frequently jump back and forth between the same longitudinal yarns in the backing thus causing gaps between adjacent rows of stitches which include as few as one and sometimes as many as three yarns of the backing material. This causes grinning and uneven rows of pile. Heretofore it has been found necessary to overcome this disadvantage by producing tufted pile fabrics with sufficient pile length so that these irregularities are substantially concealed. These irregularities occur both longitudinally and tranversely of the fabric since a relatively thick transverse yarn in the backing causes a lateral gap or irregularity in the stitch spacing which cannot be in any way controlled by adjustment of the tufting machine.

Since the pile projections in a cut pile tufted fabric naturally tend to spread more effectively than in the case of an uncut pile fabric, it is, of course, feasible to tuft a lower cut pile fabric and obtain adequate coverage than is the case with an uncut or loop pile tufted fabric. The present invention permits the provision of a pile fabric having much lower pile projections, particularly in a loop pile construction, than has previously been possible and still produce a commercially saleable fabric.

In view of the above causes of uneveness in a tufted pile fabric particularly in the case of loop pile or low pile height, it might have been assumed that the use of a uniform sheet material would overcome these disadvantages. Efforts to obtain satisfactory results using a nonwoven sheet backing material have also proved fruitless because in this case there did not appear to be sufficient friction or bind on the yarns to permit uniform control of pile height, particularly after disengagement with the loopers. The precise reasons for unsatisfactory results with sheet material are not yet completely understood. It is believed that in the case of a sheet material the needle merely punches holes which do not have sufficient tendency to reclose or grip the yarns to provide adequate or at least uniform yarn engagement as the needles are removed.

In a recent patent (US. Pat. No. 3,1 10,905, issued Nov. 19, i963 to Travis M. Rhodes) there is disclosed an improved tufted pile fabric comprising a flat woven synthetic plastic backing. For information purposes the entire disclosure of the said Rhodes patent is hereby incorporated herein by reference thereto.

Some difficulty has been encountered in attempts to commercially apply the teachings of the Rhodes patent In particular it has been observed that tufting of the primary backings disclosed in the said patent (especially such backings woven of relatively flat cross section polypropylene yarns) causes considerable rupturing and shattering of the fill (or weft) yarns. This in turn greatly reduces the strength of the tufted pile fabric produced. The considerable strength of the yarns prior to tufting somewhat alleviates this problem..l-lowever in many instances the strength of the tufted pile fabric product is low enough to make the product commercially unacceptable. To further complicate the problem it has also been observed that the appearance of the tufted pile fabric product is frequently unsatisfactory in that the pile is uneven. This is caused by tufting needles actually breaking fill yarn ends so that tufting stitches pull through and give a product having many loops.

It is a general object of this invention to alleviate the abovedescribed difficulties.

It is another object of this invention to provide synthetic plastic primary backing material adapted for use in producing high-strength tufted pile fabrics.

Another object of this invention is to provide a high strength tufted pile fabric co prising a primary backing of synthetic plastic material.

Yet another object is to provide a method for increasing the fabric strength of tufted pile fabrics comprising a primary backing of synthetic plastic material.

Still another object of the present invention is to provide a method for producing high-strength, high-quality tufted pile fabrics comprising a synthetic plastic primary backing material.

Many other objects, together with the numerous advantages of this invention will become apparent to those skilled in the art in view of the following more detailed description.

In its broader aspects the present invention is directed to improved woven synthetic plastic primary backings treated with sufficient amounts of lubricant to provide, after tufting, a tufted pile fabric having a fabric strength of at least about 50 percent of the fabric strength of the primary backing prior to tufting. In most cases fabric strength retention is as high as 70 to percent or more.

The specific amount of lubricant needed to accomplish the stated objectives will vary according to the specific lubricant used, the specific primary backing to be treated, the specific type of tufting operation, etc. In general it has been found that desired results can be accomplished by treating synthetic plastic primary backing material (for example primary backing materials like those disclosed in the previously mentioned Rhodes patent) prior to tufting with from about 0.2 to about 12, and preferably with about 0.6 to about 8 percent by weight, of a lubricant.

The synthetic plastic primary backings to which this invention may be applied include those comprised of any of the synthetic plastic materials capable of formation into weavable yarns. Such plastics include, for example, polyethylene, polypropylene, ethylene/propylene copolymers, numerous other polymers and copolymers of other alpha olefins, polyesters, polyamides, rayon, polyvinyl chloride and many other synthetic plastic materials. The invention is most especially applicable to those primary backings comprised of polypropylene yarns.

The geometry of the plastic yarns used in forming the woven primary backing may be varied considerably. The invention is most efficacious with those backings in which both the warp and the fill (or weft) yarns have a relatively flat, e.g., substan-, tially rectangular, cross section, such as those backings disclosed in the Rhodes patent previously mentioned. However, significant improvements in the fabric strength of tufted fabrics comprising primary backings in which either the warp or the fill yarns (but not both at the same time) are circular or substantially round monofilament yarn and/or yarn comprised of a multiplicity of low denier monofilament (multifilament yarn). in the latter constructions it is generally preferred to utilize the round monofilament or the multifilarnent yarn as the fill yarns together with relatively flat cross section warp yarns. These alternate constructions, per se, do not form part of the present invention and are more fully disclosed and claimed in a commonly owned US. application Ser. No. 487,402,filed Sept. 15, 1965, now abandoned and of which Ser. No. 885,083 filed Nov. 1 l, 1969 is a continuation-in-part.

The lubricant used in the practice of the present invention can be any lubricating substance that does not react with, have solvent action on, or otherwise materially affect the properties of the synthetic plastic yarns in the primary backing by chemical action. Suitable exemplary materials include mineral oil; oxyethylated higher fatty acids (i.e., fatty acids having about eight carbon atoms or more) more commonly known as polyethylene glycol esters, e.g., polyethylene glycol linoleate, polyethylene glycol stearate, polyethylene glycol oleate, polyethylene glycol laurate, oxyethylated mixtures of the fatty acids in naturally occurring higher fatty acids in various been woven experience to date has indicated that treatment can range from about i to about 12 and preferably from about 2 to about 8 percent by weight of lubricant based on the total weight of the primary backing. it will be noted therefore, that vegetable and marine oils and the like; various low molecular 5 lubricant treatment of fill yarn alone can result in some weight waxes, both natural and synthetic; a wide variety of 'sa ings in the amount of lubricant needed. well-known, nonionic surface active agents other than the ox- Regardless Of the point in time Of the lubricant treatment, it yethylated higher fatty acids previously mentioned, e.g., those can be dily accomplished by spraying, dipping. g. sold under the trade names Pluronic, Carbowax, etc.; and ethel'wise pply ng the lubricant a Solution (P v many other like materials easily recognizable to those skilled m that the solvent has t the Plastic y r emulsion in the art. Preferably the lubricant should be a relatively lowing the same to the plastic yarn prior to weaving, or to viscosity liquid either as such or when in water emulsion, so as the P y hacking after it is wevehto provide easy application and spreading. The most especially The ihYehtleh is illustrated in the following hohhmitihg preferred lubricants (based on experimental results to date) as P are mineral oil and the polyethylene glycol oleate (having an EXAMPLE 1 average of about ,oxyethylene (TCH*CH=O groups A primary backing was woven from polypropylene ribbon E 23? commercially sold under the trade name Nopcostat yarns in a conventional pattern of i5 warp yarns and I0 fill Treatment of the synthetic plastic primary backing material yargs is on a laboratory scale to Produce a backing I with the desired lubricant can be accomplished in a variety of yar T e warp yafns were "9 lubncated' The yafns ways. it is for example permissible to treat either the respecwere lubncated the l' posslble extent by f draw'ns tive warp or fill yarns or both warp and fill yarns with the lubrithrough a bath Ff lf glycol oleme lubrlcam P' cant prior to weaving them to form the backing. it will be clear Stat 1 Swing lubrlcaht treatment far in excess of that that lubricant treatment can take place after the primary .25 normally 8 in cohvehtlohal Y processing- The backing material is woven but before it is tufted. This may or 1 heavily lubricated fill y was quilled a Conventional may not be a preferred procedure depending upon the par- Whitin quiller, over end. For comparison unlubricated fill ticular plant in question i.e., whether weaving and tufting are y rn were W n in i en ical manner intO primary backings. performed in-line or in the same plant facilities and whether Each of the primary backings thus prepared was tufted on a the weaver or tufter is capable of or willing to become capable laboratory scale 14-inch wide tufter using 10 stitches per inch of performing the lubricant treatment. and 6.5 rows per inch of 3700 denier Type 501 nylon and V4 in a ptesehtly P embodiment the lubricant inch pile height. Results are summarized in the following table m equi e for t tsrrsst s f the Pre s! vsntissis 29-. V r TABLE '1 Average fabric fill Average fabric warp strength 1 strength I Fill yarn Run Warp and flll yarn lubrication Untufted Tufted Untulted 'Iultcd 1 1080 denier polypropylene ribbon None 84 27 200 155 100 mils wide, 2 do Yes s4 74 179 183 3 Same as 1 for warp; 1080 denier ptlly- None 104 25 200 140 gi'lopylenc ribbon, 130 mils wide, for 4 "do Yes 109 as 192 165 l Determined on Instron tensile tester using a 4 by 6 inch test sample (6 inches in test direction), a distance of 3 inches between laws, :1 12 inch per minute Care is taken in placing samples in jaws to be sure that the same individual jaws. The results are reported in pounds required average of 4 separate tests on till direction samples complished by excessively lubricating the warp yarns prior to placing them on the loom beam used in the weaving operation. This essentially eliminates the need for lubricating the fill yarns. It is to be understood, however, that lubrication of the fill yarns alone will also accomplish the desired results.

As indicated previously, the invention is broadly directed to lubricant treatment sufficient to provide percent or more fabric strength retention in tufted pile fabrics utilizing synthetic plastic primary backings. The basic purpose of the lubricant treatment is to deter physical damage to the fill yarns by the tufting needles in the tufting machine. This could per- I haps be accomplished by lubricating the needles themselves but this is believed to be impractical for the tufter.

As indicated above lubrication of the fill yarns alone will satisfy the purposes of this invention. Present experience indicates that treatment of fill yarns with from about 0.5 to about [0 percent by weight, and preferably about 1.5 to about 7 percent, based on the yarn weight, together with no lubricant treatment of the warp yarns, gives quite satisfactory results. inasmuch as the fill yarns comprise about 40 percent of the total primary backing the filling yarn treatments stated correspond approximately to about 0.2 to about 4 (preferably about 0.6 to about 3) percent by weight of lubricant, based on the weight of the total backing.

When treating both the warp yarns and the fill yarns before weaving, or when treating warp yarns alone before weaving, or when treating the synthetic plastic primary backing after it has constant jaw travel rate and jaws 1 inch wide and 1% inches long. to break I b l i hyarns are gripped by the rcspcctiv per a r e no (lbs/inch). 0 values shown are as? 3. 1 3 wt rfli s ibss The striking differences in fabric strength retention after tufting, particularly in the fill direction, are readily apparent from the data of table l.

in addition it was observed that tufted appearance was grossly different. Both lubricated samples (Runs 2 and 4) had good pile evenness. The unlubricated controls (Runs 1 and 3 representing known primary backings, each had many loops caused by tufting needles actually breaking filling ends so that tufting stitches pulled through.

EXAMPLE 2 A polypropylene yarn primary backing identical to that of Run number 2 of example 1 was prepared and tufted by a commercial carpet manufacturer in a zigzag, 7% stitches per inch and 6% rows per inch. Average fabric strengths, in the fill direction, determined as described in footnote 1, table 1 were:

Untufted-93 pounds per fabric inch Tufted-70 pounds per fabric inch For comparison a commercially available woven jute primary backing (l6 warp yarns per inch and I3 fill yarns per inch) was tufted in an identical manner. Average fabric fill strengths were:

Untufted-7l pounds per linear inch Tufted-25 pounds per linear inch Example A polypropylene yarn primary backing identical to that of Run number 4 of example 1 was prepared and tufted by a commercial carpet manufacturer 9% stitches per inch, 9% rows per inch with a cut pile one-fourth inch high after which the tufted pile fabric was piece dyed. Average fabric strength (3 samples) in the fill direction after tufting and dyeing was 82 pounds per fabric inch. All samples tested in the warp direction gave fabric strength results greater than 200 pounds per inch.

EXAMPLE 4 In this example further polypropylene ribbon primary backings substantially like those in Runs 1 and 2 of example 1 were prepared. The backings of this example were woven 12 feet wide on a commercial loom using a Unifil quiller with no lubricant applied to the fill yarns. The warp yarns were very heavily lubricated with Napcostat 2152-? prior to placement on the loom beam used in the weaving operation. Paired samples of the primary backings so prepared were tufted with and without preliminary heat setting of the backing on a tenter frame. Tufting was substantially identical to that used in example 1, the only difference being tufts at 9% stitches per inch instead of 10 stitches per inch. in addition still further backing samples were tufted at 6% stitches per inch with no preliminary heat setting of the backing. Results are summarized in table ii. The average fabric strengths were determined as described in example 1 except that untufted strengths represent an average of three instead of four readings.

TABLE II Average fabric strength (fill direction) Tutted.9% stlches per inch Not Tufted heat Heat 6% stitches Untufted set set per inch Run No When samples were woven and tufted in exactly the same manner except for lubricant treatment of the fill yarn in addition to the very heavy treatment of the Warp yarns results were as follows:

TABLE IIA Run No l The difference between runs 0 and d was the use of a different lubricant and lubricant concentration. Both lubricants used are commercially available materials.

The results shown in tables 11 and 11A show that lubricant treatment of the fill yarns is not needed to get good tufted fabric strength when the warp yarn is very heavily lubricated prior to weaving. This is a highly significant advantage in view of the difficulties sometimes experienced in quill weaving with highly lubricated fill yarns.

The results further show that heat setting (1 minute at 280 F.) had little or no significant effect on tufted fabric strength.

EXAMPLE 5 commercially available polyethylene glycol oleate (Nopcostat 2152-1). The strength retention values presented are calculated from the formula:

Yarn tensile strength after weaving and Tufting Initial tensile strength of yarn Percent Strength retention= Results are summarized as follows:

As previously noted the above structures, per se, are more fully disclosed and claimed in commonly owned U.S. application Ser. No. 487,402 filed Sept. 15, 1965, now abandoned, of which application Ser. No. 884,083 filed Dec. 11, 1969 is a continuation-in-part.

Variations and modifications of the instant invention will become apparent to those skilled in the art upon reading the foregoing description and illustrative examples. All such variations and modifications are considered to be within the scope of the appended claims.

Many advantages of the present invention have been fully described and illustrated hereinabove. it is also expected that the invention will result in a substantial increase in tufting efficiency in commercial operations with little or no additional cost to the commercial tufter. In particular there surely will be less wastage (in view of the greatly improved tufted pile appearance). Moreover, substantially less down time because of tufting yarn breakage is expected in view of increased ease of tufting and resultant decreased strain on tufting yarn in the tufting needles.

I claim:

1. A high-strength tufted pile fabric comprising a woven primary backing material, said primary backing woven of yarn of a plastic selected from the group consisting'of polypropylene and copolymers of propylene, at least some of said yarn in said primary backing having a relatively flat cross section; said substantially flat year being coated with a lubricant in an amount in the range of about 0.2 to 12 percent based on the weight of said yarn, and a plurality of tuft, a substantial number of said tufts penetrating some of said lubricated substantially flat yarn, said penetrated yarn being relatively free of ruptured and shattered areas compared to an unlubricated penetrated yarn in otherwise similar fabric.

2. A high-strength tufted pile fabric comprising a woven primary backing material, said primary backing woven of yarn made from a polymer selected from the group consisting of polypropylene and copolymers of propylene, at least some of said yarn in said primary backing having a substantially flat cross section, said substantially flat yarn coated with an agent that is essentially nonreactive with and having essentially no solvent action on said yarn, said agent being present in an amount of about 0.6 to 8 percent based on the weight of said yarn, said agent being selected from the group consisting of mineral oil and oxyethylated higher fatty acids, and a plurality of tufts, a substantial number of said tufts being inserted through said woven primary backing with a frequency of more than 6% tufts per inch, some of said tufts that are inserted with a frequency of more than 6 /2 tufts per inch penetrating some of said lubricated substantially fiat yarn, said penetrated yarn being relatively free of ruptured and shattered areas, said high-strength tufted pile fabric having a fabric strength in the till direction of at least 50 pounds per linear inch.

UNITED STi-XTES P1; "51??? OFFICE CERTIFICATE OF COEHSEC'EEON Patent NO. D t d 1.9, Inventor(s) Carroll Trowbridge Kennedy.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 68, cancel 'Ser. No. 885,083 filed Nov. 11, 1969" and insert --Ser. No. 884,083 filed Dec. ll, l969--;

Column 6, line 46, cancel "year" and insert --yarn--;

line 48, cancel "tuft" and insert --tufts--.

Signed and sealed this 19th day of December 1972.

(SEAL) Attest:

EDWARD M.FLE'I'CHER, JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Pateni 

2. A high-strength tufted pile fabric comprising a woven primary backing material, said primary backing woven of yarn made from a polymer selected from the group consisting of polypropylene and copolymers of propylene, at least some of said yarn in said primary backing having a substantially flat cross section, said substantially flat yarn coated with an agent that is essentially nonreactive with and having essentially no solvent action on said yarn, said agent being present in an amount of about 0.6 to 8 percent based on the weight of said yarn, said agent being selected from the group consisting of mineral oil and oxyethylated higher fatty acids, and a plurality of tufts, a substantial number of said tufts being inserted through said woven primary backing with a frequency of more than 6 1/2 tufts per inch, some of said tufts that are inserted with a frequency of more than 6 1/2 tufts per inch penetrating some of said lubricated substantially flat yarn, said penetrated yarn being relatively free of ruptured and shattered areas, said high-strength tufted pile fabric having a fabric strength in the fill direction of at least 50 pounds per linear inch. 